Struct trackball::Touch

pub struct Touch<F: Debug + Eq, N: Copy + RealField> { /* private fields */ }

Touch gestures inducing slide, orbit, scale, and focus.

Implements Default and can be created with Touch::default().

All methods except Self::fingers() must be invoked on matching events fired by your 3D graphics library of choice.

Implementations

impl<F: Debug + Copy + Eq, N: Copy + RealField> Touch<F, N>

pub fn compute( &mut self, fid: F, pos: Point2<N>, mvs: usize ) -> Option<(usize, Point2<N>, N, N)>

Computes centroid position, roll angle, and scale ratio from finger gestures.

Parameters are:

• fid as generic finger ID like Some(id) for touch and None for mouse events,
• pos as current cursor/finger position in screen space,
• mvs as number of finger moves for debouncing potential finger tap gesture with zero resulting in no delay of non-tap gestures while tap gesture can still be recognized. Use zero unless tap gestures are hardly recognized.

Returns number of fingers, centroid position, roll angle, and scale ratio in screen space in the order mentioned or None when debouncing tap gesture with non-vanishing mvs. See Self::discard() for tap gesture result.

Panics

Panics with more than ten fingers.

pub fn discard(&mut self, fid: F) -> Option<(usize, Point2<N>)>

Removes finger position and returns number of fingers and centroid position of tap gesture.

Returns None as long as there are finger positions or no tap gesture has been recognized.

Discards finger positions and tap gesture if generic finger ID fid is unknown.

pub fn fingers(&self) -> usize

Number of fingers.

pub fn cast<M: Copy + RealField>(self) -> Touch<F, M>

where N: SubsetOf<M>,

Casts components to another type, e.g., between f32 and f64.

Trait Implementations

impl<F: Clone + Debug + Eq, N: Clone + Copy + RealField> Clone for Touch<F, N>

fn clone(&self) -> Touch<F, N>

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<F: Debug + Debug + Eq, N: Debug + Copy + RealField> Debug for Touch<F, N>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<F: Default + Debug + Eq, N: Default + Copy + RealField> Default for Touch<F, N>

fn default() -> Touch<F, N>

Returns the “default value” for a type.